diff options
Diffstat (limited to 'fs/ext4/page-io.c')
| -rw-r--r-- | fs/ext4/page-io.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 755741c211a4..0f65561ab5a5 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -158,7 +158,14 @@ static void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end) wake_up_all(ext4_ioend_wq(inode)); } -/* check a range of space and convert unwritten extents to written. */ +/* + * Check a range of space and convert unwritten extents to written. Note that + * we are protected from truncate touching same part of extent tree by the + * fact that truncate code waits for all DIO to finish (thus exclusion from + * direct IO is achieved) and also waits for PageWriteback bits. Thus we + * cannot get to ext4_ext_truncate() before all IOs overlapping that range are + * completed (happens from ext4_free_ioend()). + */ static int ext4_end_io(ext4_io_end_t *io) { struct inode *inode = io->inode; |